The blood vessels and arteries, lymphatic vessels, the ureters of the urinary system, and other ducts within the human body, are subject to degradation. Weaknesses in the walls of these ducts may result from a number of different reasons, such as a ureter being compromised by a kidney stone, or a blood vessel weakening due to atherosclerosis and aging. A minimally invasive surgical treatment for weakened, aneurysmal, or ruptured vessels may comprise the introduction of prosthesis within the lumen. The prosthesis, which often may be a stent, serves to restore some or all of the functionality lost through the deterioration of the vessel and/or bolster the duct's integrity at the site of weakness.
There are many devices that have been developed to introduce a stent into the inner open space or “lumen” of these vessels and ducts. A representative example of these devices is shown by the invention in U.S. Pat. No. 7,867,268 to Shelso, titled, “Stent Delivery System for Self-Expanding Stent.” In Shelso, as with virtually most of these devices, a catheter assembly comprises an outer tube, into which a self-expanding stent is loaded, and also comprises a slidable inner tube connected to a tip. The catheter is inserted into the vessel lumen and advanced to the site that is slated to receive the stent. Once properly positioned, the outer tube is backed outward relative to the inner tube with the result that the stent is introduced beginning from the far end- the distal end- and progressively released out from the outer tube to self-expand to contact the vessel wall, until the proximal end of the stent is similarly released and installed. The catheter of the delivery device may then be removed.
A major drawback of all of these devices is that they install the stent in the distal-to-proximal direction. These are several scenarios where the typical distal-to-proximal deployment is highly undesirable, and a means of positioning the stent to have one end at an exact proximal location-requiring a proximal-to-distal deployment-would be extremely advantageous, because placement of the stent at such a proximal location is critical in certain scenarios. Some examples of such scenarios are: where the self-expanding stent is to be deployed in proximity to a location where a side branch originates and the side branch is not to be covered; where a stent is needed to be deployed to overlap another previously installed stent more proximally; and to cover the Ostia of a lumen. The invention herein comprises a new apparatus and corresponding method to achieve a reverse stent deployment installation, to ensure critical proximal stent positioning.